A charged particle beam device represented by an electron microscope is a device that accelerates a charged particle beam emitted from a charged particle source and that irradiates a sample with the accelerated beam. A scanning electron microscope is provided with, for example, an extraction electrode for extracting a beam from an electron source, an accelerating electrode for accelerating the beam extracted from the extraction electrode, a scanning deflector for scanning the beam on the sample, an aberration corrector for correcting an aberration, an electrostatic lens, and a corrector for adjusting an orbit of the beam so as to pass an ideal optical axis of these optical devices.
These optical devices are for controlling the beam by an electric field generated by applying different voltages to plural different electrodes, and such plural electrodes forming the electric field need to be properly insulated so as not to be conducted.
In Patent Literature 1, an electron gun using a conductive insulator for an accelerating tube is disclosed. When the conductive insulator is used for the accelerating tube, charges generated by collision of an electron beam on a surface of the insulator flows on the surface of the conductive insulator as electric current, therefore, charge-up can be suppressed. In Patent Literature 2, an electronic optical lens barrel formed of conductive, though high-resistance, ceramics is disclosed. As a tube body of the lens barrel, especially an inner tube is made to be highly resistant and conductive, a charge-up amount between electrodes can be reduced. In Patent Literature 3, a method of suppressing charge-up of an electrostatic deflector in an electron beam exposure device by covering an electrode surface with vanadium dioxide (VO2) is explained. Furthermore, in Patent Literature 4, an electrostatic deflector interposing an insulating member such as a glass substrate between electrodes is explained. In Patent Literature 5, an electrostatic deflector in a charged particle beam exposure device is formed of a composite material including non-magnetic oxide particles such as CaVO3 and inorganic glass is explained.